Process of manufacturing titanic oxide suitable for use as alpha pigment



lPatented Apr. l2, 1932 uurs yKani; nupcias, orinnnLIN-znnignnnonr,emiliani' Pnocnss or Mauuracrie-Limita'ritrnivrcl Voxinn suirmnnroii USE As A P'IGMENT No Drawing. `.Application filed lovember L20, r19126Seria1 No. 149,800, andan rGermany'November 27, 1925i.

My invention'relates to improven'ientsin the process of manufacturing `titanic ,oxide suitable for use asa pigment;

vVihen rendering titaniumores sucli` as fili f- 5 menite or rutile soluble by means of sulfuric' acid orV bisulphatefof sodium ('NaHSO4) and dissolving the product" in Water solutions are.'

' iron compound.

trations of sulfuric acid which do not per#L mit precipitation of the iron oxide from the saidsolutions of the ores, the titanic oxide is almost completely precipitated frointhe solution containing the titanium hydroxide at the temperature of boiling Water and under atmospheric pressure. Thus, inmy improved process the concentration of the sulfuric acid Vand the titanium compound may be such that the hydrolysis and the precipitation'of iron is prevented. rTherefore my process consists in first rendering the titanium ore soluble-'by means of sulfuric acid or bisulphate of sodium, dissolving the product in Water, transforming the sulphate of titanium into the hydroxide by adding a suitable base, preferably magnesium oxide distributed in Water, separating the titanium hydroxide Which still contains Va high proportion of iron, redissolving the impure vhydroxide in sulfuric acid of suitable concentration, andV finally precipitating the' titanic oxide by tion of the titanium ore, andthat it is suffiheating the solution at the temperature `of boiling Water and under atmospheric pres` Vcient to precipitate onlyva part thereof, andi to dissolve the precipitate in the other part of the solution of the ore. f Thus'on the onel hand 4Va high concentration ofv titanic oxideY in the solution gis obtained, 'so that theV solu- 65 tion to be heated is comparatively small, and

`on theother lhand they solutions lcanbev sol concentrated that the sulfuric acid set free by the hydrolysisof the titanium sulphate ,is sufficient to'prevent the hydrolysisof kthe 60 Examplep-100 kilogrammes "of ilm'enite are made soluble byf'the vproper'amount VofV sulfuricgacidfandl WaterV is added so thata solution of about40Q liters isobtained. The 05 Fe'f -lf "-l is reduced-to Fe-l f ,by any known process. A partfof lthe iron sulphate lis crystallized at normal or reduced: l temperature.

yNovv a part of the solution, say .aboutfvQOOy liters,`is precipitated by means of so much of a 'suitable'basepreferably oxide of mag# ne'sium distributed viny Water that all.` the' sulfuric acid lexcept that vpresent in the FeSO; f is'neutrali'zed.'l The'precipitate is separated in a filtering press and redissol-ved inthe 200 75 Y' liters yof the remaining VAsolution of the fore.V Thus a solution'is 4produced Which contains titanic-oxide :and sulfuric'acid substantially at the ratio `of one molecule of titanic-oxide and'one molecule'of sulfuric acid, Whileinthe 80 original solutionobtainedby rendering the-` oresolubleqbylmeans ofsulfuric acid anddissolving thesa-me in Water the said compoundsl .are atthe .rate of tWo molecules'of sulfuric acid and one molecule'of titanic-oxide. f The 85 relative amountfof titanic-oxide is increased vandthe relative amount of iron is reduced f accordinglyQ'The solution thus obtained'js heated' at a temperture'of/ aboutf'IlOOo C., Whrerebyl about of? the titanic oxide is 90` precipitated, the precipitate being free of iron", vprovided that the concentration of the ,f sulfuric acid, bound to titanium, in thei last named solution is not'less than about18%.

easily filtered, and, Aafter being further treatedjyitlis a highclassiwhite pigment.` u il' enf adding moresulfuricacid to the"L solutionathe:output'is slightly reduced', but in I any case it is,4 satisfactory, even ifV the con- 100v TheV precipitate'is lr'mlverulent,andcan be 95 Y centra-tion of the sulfuric acid is higher than that contained in the solutions of the ore which at a temperature of 100o G. do not result in precipitation. Small amounts of a sulfuric acid which are always present in the air-.hydroxide by means of magnesium-oxide,

separating the precipitate, dissolving theV precipitate in sulfuric acid, and heatingfth solution. I

2. The herein described process Yof manu- `V-:ffacturing titanic-oxide from titanium ores,

Which consists in rendering 4titanium ore soluble by means of sulfuric acid,rdissolving the product iny Water, precipitating titanium hydroxide by means of magnesium-oxide,

"separating the precipitatddissolving the precipitate in so'much sulfuric acid that the concentration of the free acid and that bound to the titanium is not less than "about 1.8%, and heating the solution.

3. The herein described process of manufacturing titanic-oxide from titanium ores, which consists in renderingtitaniiim @resoluble by means of ysulfuric acid,.dissoflving. the product in Water, precipitatingtitanium v*hydroxide from a part of the solution by means of magnesium-oxide, separating the precipitate, dissolving the precipitate in the remainder lof the solution of the' ore, and`V heating the solution.k n

4. The herein described process of manufacturing titanic-oxide' from titanic ores,

which consists inrendering titaniuiiioreisol-Y uble by means of sulfuric acid, dissolving. the product in Water, precipitating titanium hydroxide by means of magnesium-oxide,

separating the precipitate, dissolving the precipitate in so much sulfuric acid that sulfuiic acid and titanic-oxide are substantially,Y at the ratio AVof one molecule of' sulfuric acid-V and one molecule of titanicLoXide Vand that precipitate, dissolving the precipitate in the remainder of the solution of the ore so that titanic-oxide and sulfuric acid are in the solution at the ratio of one molecule of titanicoxide and one molecule of sulfuric acid and the solution contains not less than about 18% of S()4 ions bound to titanic-oxide, and heatingl the solution.

6. The herein described process of manufacturing titanic-oxide from titanium ores, which consists in rendering titanium ore soluble by means of sulfuric acid, dissolving theproduct in Water, precipitating titanium hydroxide from a part of the .solution by means of a base, separating the precipitate, dissolving the precipitate in the remainder of the solution ofthe ore so that titanic-oxide and sulfuric acid are in the solution atvthe ratio of one molecule of titanio-oxide and one molecule of sulfuric acid and the solution contains not less than about 18% of S04 ions bound to titanic-oxide, and heating the solution.

In testimony whereof I hereunto affix my signature.

KARL LEUCHS. 

